Method of producing electric light.



No. 843,534. PATENTEDFEB. 5, 1907.

P. G. HEWITT.

METHOD OF PRODUCING ELECTRIC LIGHT. APPLICATION FILED arm. as, 1900.

2 BHBETSSHEBT 1.

FAiw CE'W bur/1101' by f -i44 Afi'y No. 843,534. PATENTED FEB. 5

P. G. HEWITT. METHOD OF PRODUCING ELECTRIC LIGHT.

APPLICATION FILED SEPT. 28, 1900.

2 SHEETS-SHEET 2.

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[We/liar W UNITED. STATES mran'r OFFICE.

PETER COOPER HEWITT, OF NEW YORK, N. Y., ASSIGNOR, BY MESNE ASSIGNMENTS, TO COOPER HEWITT TION OF NEW YORK.

ELECTRIC COMPANY, A CORPORA- METHOfi OF PRODUCING ELECTRK) LIGHT.

No. 843.534. Original application filed April 18,

Specification of Letters Patent.

, 1900, emu No. 19,291. mean and as application filed September 28, 1900.

Serial No. 31,346.

To all whom it may concern.

Be it known that 1, PETER Coorna HEW- I'm, a citizen of the United States, and a resident of New York, in the county of New York and State of New York, have invented a certain new and useful Im rovernent in Methods of Producing Electric 'ght, of which the following is a specification.

The existing state of the art of lighting by electricit resents various forms of lam s and met 0 s of lighting. In my lamp t e actual light-generating current is induced in the medium where the light is generated, the current being what is known as a secondary current.

The present invention relates to a method of lighting by means of my improved lamp, the .ap aratus itself and the system .under which it operates being claimed in a separate application, filed April 18, 1900, Serial No. 13,291, of which this applic'ation'is a division.

Broadly,it relates to a method of lighting which shall yield a practical light without any conductor leading into the lamp, thus making it possible to dispense with any break or joint in the electric circuit. ThisI accomplish by using vapor or gases of proper charactor and under proper conditions as the medium for transformin the electric ener into light, the energy eling caused to e present in the va or. or gases which serve as a conductor by in nation. Iii-this we I dispense with conductors leading into t e contained vapor or gas through the walls of the. container. 9 a

It may be enerally stated that .a coil of wire traverse by a varying currentof electricity is surrounded by a varying magnetic field consisting'of s0called magnetic lines of force. F The fieldof force thus established, however,varies in proportion with thevariations oftth'e current;ran'd if a closed circuitsuch, for instance, as a coil of wire'be properly placed within this varying field of force there will be induced in ita 011118111300116- s ending to the variationsin the fielder force."

device of this character is usually termed an,

be substituted for" thej secondaryc'oil of the in it if the rate of change is suitable. The energy of such current will manifest itself in the form of light and heat if suflicient lines of force are cut by the vapor to overcome its tendency to resist becoming a conductor.

yoltage depend upon the general laws of induction-namely the relation of theturns in the primary to those in the secondary and the rate of change of the pulsations or variations in the actuating or primary current or, in other words, the rate at which the magnetic lines due to the primary current are cut by the seconda circuit. This rate is the the secondary circuit.

, In the form of lamp which I have devised it is practicable to employ for the secondary circuit a simple closed circuit of vapor having effectively one turn in connection with a multipletur;n rimary giving a suitable ratio of step-down ransforrnation.

or the purpose of developing an electromotive force in the secondary sufiicient to place it in 'a'state conductive that of low resistance-I make use of a'current of such quantity and rate .of variation in a prim of such multi inter-linkage as wil secondary an electroinotive force which shall the va or to resist becoming a conductor, notwit' tending the decrease of electromore uired interlinkage with the said vapor seconary;

The vapor use is that obtained from mercury, because of used, theuse' of any vapor'beingdepen only upon the requirement come its resistance. Certain irn pore added to the waporswh c or forming thesecondary or light-emitting} circuit xcrcise such sage of the electric current that it is induce a secondary current in the l current to Patented Feb. 5, 19Q7.

and the energy of such current will be induced 'be sufiicient to break down thetendenc'y of such multiple-turn'primary as will give the its low resistance; but other materials may be ent'" that there shall 'bemduced init a voltage sufiicientto oven 1 uritiesorvm" areselected If? rob a'reluctance to the Pag almostw impossiblewith the most rapid variationof' The" induced current in thelamp and its 1 measure of the e ectrornotive force given to where it will become readily is, a true vapor-conductor I licity of turns and such inducei'n one turn of a tive force which must result from the use of which Ifind most convenient in lamp when they are present. Such vapors as will be obt ained from water and some oxygen com ounds seem to have this state of non-cont uctivity in a marked degree. Also the vapors usually resent in a lobe until it has been exhausted heated, and the current induced in it, which current liberates more non-conductin vapors, would seem to render the desired state of conductivity almost impossible to attain; but by properly pipeparing the lamp and supplying the globe with the conducting-vapor freed from the objectionable ones a condition is reached where a practical and enduringlamp is obtained. The conducting-vapor when in its conducting state, being a conductor requiring a rate of change in the primary that will induce in a secondary of one turn an electromotive force of, say, from three to fifty volts per inch in case the secondary is, say, three inches in diameter, the inducing-current need not be over a few hundred volts when the current is passing in the vapor, the voltage depending upon the materia of the vapor, its density, and other conditions.

The amount oflight emitted by the gas readily shows at what time during the procass of manufacture the lamp is completed.

I am aware that others have roposed certain lamps claimed to be in notion-lamps having a luminous band induced therein; but in none has any considerable amount of light been produced.

My lamp yields a large quantity of light and possesses other characteristics which clearly distinguish it from the faint luminosity of the electrostatic efi'ect produced in the lamps above alluded to. The difference is also at once apparent in the source of current.

In tie operation of tie lamp the voltage required to cause current to pass in tie ring or body of vapor appears to decrease suddenly after a suitable degree of induction is arrived at, indicating that some radical change of claracteristics takes place. Tle resistance tends to vary inversely with tie current passed, as shown by otier experiments with vapor conductivities, wit ere tlie vapor secondary is included in inductive relation to an oscillatory current flowing in an oscillatory circuit. to oscillatory efl'ects are practically annulled as the vapor secondary, when tl;.is condition is arrived at, will absorbin the .first oscillation practically all of the energy that is present in the oscillatory circuit. This may be demonstrated by means of a tertiary circuit of a single turn of wire, including an incandescent lamp, which when the vapor secondary is not present will become luminous and carry current; but when a vapor secondary 1:.avi tire cl: aracteristics of mylampis introduce ininduetive relation to the primary it will absorb tlie energy delivered to tie primary, and thus rob the tertiary circuit, so that the incandescent lamp will no longer be illuminated and practically no current will flow in the tertiary circuit.

'lle invention will be described more in detail in connection with the accompanying drawings.

Figure 1 is a diagrammatic view of one form of my lamp connected with a generator. Fig. 2 is an elevation of one form of my lamp, using two primary coils. Figs. 3, 4, 5, 6, and 7 are views showing otler forms of lamp. Fig. 8 is a diagranunatic view of several lamps and a form of generator in circuit therewitn.

Referring to the drawings, 1 is any suitable source of rapidly-varying currents, and 2 is a closed container, tie slf ape of wlicli may be varied to suit tlie circumstances. Witi in tile vessel 2 tile-re is placed ti e desired vapor or gas of suitable density to be rendered liglt-radiant or light-emitting. A coil 3 of insulated wire of tr e proper number of turns constitutes the primary coil of tie transformer, tit e vapor or gas wit? in ti; e vessel being tie secondary circuit. T'i'e coil 3 is connected with tie energizing-coil 1. On tie passage of a current of ti e proper character through the coil 3 a current is induced in the vapor. Immediately tlie vessel becomes brigltly luminous. A c? ange in position of the primary coil causes a corresponding 01: ange in tie position of the luminosity. By increasing the amount of energy imparted from ti e primary sourcepracticaily all of the vapor in the lamp may be made to act as a secondary and to give tl'e lamp a very intense brigl...tness. 1? e addition of a second coil 4 on tle globe of the vessel 2 (see Fig. 2) causes an increase of luminosity.

In Fi 3 a form of lamp is shown in w. ich one bulb 2 is made with a nan'ow neck and a coil 3 encircles tl'e narrow portion. Ti e operation is essentially tlte same as t1 at described with reference to Fig. 1.

In Fig. 4 a form is shown consisting of two hemispherical bulbs 2 2 itaving suitable depressions in their faces or receiving the coil 3. The bulbs are then placed togetl'er with the coil 3 between ti em and currents t7? rough tltis coil act upon tle contents of both bulbs.

In 'Fig. 5 a modification is slown in w ich three bulbs 2 2 2 are sltow-n arranged in close proximity to each 0t? er with coils 3 3 3 placed between t1 em. Tlese tiree coils may be comiected in series or in parallel, as desired.

As already stated, the va or which I find very convenient for use is t at of mercury. This vapor offers a low resistance and produces a very intense white light. Other gases or vapors may, however, be used, care eing taken to select, such as will receive current under the influence of such a voltage as may be induced therein, and the light emitted thereby will correspond to the spectrum of that gas or vapor.

IOC

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I able rate of variation. I

" my lamp.

' shall remain in the lam The operation of the lamp depends upon the possibility of obtainin a current of suitave obtained ex cellent results by the use of the discharge-currents obtained from condensers; but a pro erly-constructed mechanical generator won (1 produce the necessary current.

In Fig. 8 I have represented diagrammatically one form of apparatus giving a rapidlyvarying current suitable for use to o erate This generator is indicate at 11 and produced an alternating current of, say, one hundred and twenty-five to three hundred eriods per second and of a voltageTglf, r e

say, om fifty to one hundred volts. generator supplies the primer coil 12 of a transformer, t e secondary coi 14 deliverin an induced current of, say, six thousan volts. This induced current is delivered to condensers 15 of suitable capacity, which may be arranged to be discharged through the line 16. I usually prefer, however, to use two condensers 15 15, as shown, using the current induced between them throng the line 16. The discharge-gaps 17 limit the charge of the condensers and serve to dis-] charge them. Other forms of discharge devices may be emplo ed--as, for instance, the well-known vaporischarge devices disclosed In manyof myearly atentsanda plications. Each time the con ensers are charged and discharged the current induced between them will flow back and forth through the line 16. One of the vessels 2 being placed in the field of t e coil'3 will act as a secondary, tapping off the amount of current that the lam is constructed to take. The coil 3 thus ecomes the primary and the vapor in the vessel the secondary of my vapor transformer or lamp. With a pressure of six thousand volts and a bulb sixinches in diameter a coil 3 of fifteen turns will serve to illuminate the bulb, With bulbs having other characteristics the best number of turns may be determined b trial.

In manufacturing my lamp I usual proceed as follows: The lamp is conneote' with an exhaust-pump to remove the water'and any. vapors that ma be contained in the glass ofithe bulb, the 'ulb'being heated durmg the process of exhausting. I then intro duce or generate in the lamp the vapor' upon' which I desire tooperate and-which is to act as the secondary still retaining the connection with the exhaust-pump, usually introducing more of the vapor than it is intended when completed. While still connected wit the exhaust-pump I place a coil, such as the rimary 3, Fig. 2, in such position that its fie d ma include the bulb and its inclosed vap'or. here is then passed through this Hrimary coil a rapidllp varying current, an the effect upon. t e vapor in the bulb is carefully noted. After the foreign and objectionable gases have been um d out and thegas or va or which is to e il uminated has reached t e proper density the bulb receives the desired amount of current and becomes brilliant. It is then sealed off from the pump andis finished.

The light produced bythislamp is an intensely luminous li ht in distinction from the foggy or hazy con ition which may be produced by means of electrostatic effect. In the producton'of niylamp's this foggy or hazy effect is reduced during their reparation, usuall uring the period of exhaustion before t e density of the ultimate conducting vapor has been regulated and always in highly-rarified gases with exceedingly rapid rate of variaton of thecurrent obtained from the use of small "condensers and very hi h voltage. This electrostatic efl'ect usually spaces in an ordinary carriage-wheel.

The com leted ap aratus acts like an ordinary trans ormer, t e primary in this case being the coil 3 and the'secondary' being the part 2 with its contained vapor or, more strictly, the contained vapor itself. Unless current is drawn off by the secondary the rimary, asin anordinary transformer,

hokes back the current in the line and prevents the passage of current through the pri mar coil. p

T e invention claimed is- 1. The method of producing light through the medium of an inclosed gas or vapor, which consists in inclosing in a suitable chamher, a gas or vapor-of such density as tobe capable of becomin ductive circuit, a subject' vaporto the influence of such inductive circult, the said circuit being ofsuch a character'as to inducelin the vapor-circuit currents quantity to cause the gasjor' Eattaln its state of maximum conductivity. I

a 5 2. The method pf producing light can the of sufficient vapor energy of a varying electric current, which consists in opposing to the flow of the current T the secondary of an ing the'gasor 'ap ears striated radially in a band in the tu e, the striations appearing like the open through a' circuit, a counter 'jelectroniotive force approximately equal to the applied electromotive force, and subjecting an in:

closed gas or vapor to the inductive influence of said circuit, thereby"modifying thecoun ter electromotiye force-"in proportion to the energy consumed by the current traversing the gas or vapor.

3'. The method of o crating a va or-lamp by electromagnetic in uction, Whic method consists in subjecting said lamp'to a rapidlyvarying magnetic field of such rapidit of variation and of such total energy as wi 1 cause the incloscd va or to become a low-resistance vapor-con uctor.

4. The method of operating a vapor device which method consists in transferring to the vapor by electromagnetic induction, sufiicient electric current to cause said vapor to pass its critical breakin -down point as a dielectric and to become a ow-resistance vaporconductor.

5. The method of operating a vapor device which method consists in transferring to the vapor by electromagnetic induction, sufficient electric current to cause said vapor to pass its critical breaking-down point as a dielectric and to become a conducting secondary of a resistance so low as to absorb substantially all the energy flowing in the primary circuit.

6. The method of increasing the efficiency of a Ugh-frequency transformer, having a secondary composed of an inclosed vapor, normally non-conducting but ada ted to become a low-resistance vapor-con uctor acting as a single-turn secondary, which method consists in adjusting the ratio of the stepdown transformation to the characteristic and conditions of the inclosed vapor constituting the secondary.

7. The method of increasing the efliciency of a transformer having a secondary composed of a n'iaterial normally non-conducting ut adapted to become a low-resistance conductor, which method consists in adjusting the ratio .of step -down transformation to the characteristics and conditions of the material constituting the secondary, by adjusting the number of turns of a multiple-tum primary coil.

8. The method of increasing the quantity of current tlou ing in the secondary of a stepdou'n transformer comprising a prima circuitand a single-turn secondary consisting of an inclosed vapor normally non-conducting but capable of becoming a conductor of low resistance, \xhich method consists in predetermining the number of turns of the primary to decrease the voltage and increase the quantity of tle said current to a ratio most suitable to the characteristics and conditions of said inclosed vapor. a

9. The mcthod of increasing the uantity of current llo ingin tlre secondary o a stepdo n transformer comprising a primary circuit and a secondary consisting of a material normally non-condueting but capable of becoming a conductor of negative temperature eoeilicicnt and low resistance, which method consists in predetermining the number of turns of the primary to secure the interlinkl age and uantity current with res ect to the characteristics and conditions 0 said material in such manner as to cause said secondary to reach the condition of a low-resistance conductor. l a

10. The method of breakin down a dielectric consisting of a body 0 vapor, which method consists in subjecting the va or to a rapidly varying elecromagnetic old of which the energy and interlinkage is predetermined to the reluctance and current-carrying capacity of said vapor.

11. The method of preventing oscillations in an excited oscillatory circuit wl1ich method consists in absorbing the energy thereof in a vapor secondary of such volume, density and conductivity and so interlinked ith the primary circuit as to absorb substantially all of the energy of the latter w ithin the time of the natural period of a single oscillation thereof.

12. In the art of producing light by elec tromagnetic induction in an inclosed vapor, the method of impressing large amounts of energy upon said vapor, which method consists 1n causing rapidly-varying currents to traverse the multiplicity 0 turns of a primary coil in inductive relation to said vapor and predetermining or adjusting the quanti ty of the current-supply in accordance vs ith the number of turns of the primary and the characteristics and conditions of the vapor.

13. In the art of operatin vapor-lamps b electromagnetic induction, iii consists in constitutin the va or of aid lamp the secondary o a step own transformer and compensating for the resulting reduction of the voltage impressed upontlze e method wLic vapor by increasing the quantity of the current flux in the primary coil.

14; The method of operating a vapor-lamp which method consists in transferring to the vapor by electromagnetic induction, sufficient current to cause said vapor to pass its critical breaking-down point as a dielectric to pass the condition of high resistance and to ecome a low-resistance vapor-conductor.

Signed at New York, in the county of New York and State of New York this 24th day of September, A. D. 1900.

PETER COOPER HEWITT.

Witnesses:

WM. H. CAPEL, WILLIAM L. Hnwson.

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